Split the Kernel transformations into modular and global ones

pkg/kernel/lib/target/flutter.dart

Index: pkg/kernel/lib/target/flutter.dart
diff --git a/pkg/kernel/lib/target/flutter.dart b/pkg/kernel/lib/target/flutter.dart
index 5673a22a570145ed89a58c602e3bdc8bacc9c529..4ba79644c2b45edd71f4360bb881edd12fc4ffb7 100644
--- a/pkg/kernel/lib/target/flutter.dart
+++ b/pkg/kernel/lib/target/flutter.dart
@@ -50,8 +50,11 @@ class FlutterTarget extends Target {
         'dart:vmservice_sky',
       ];
 
-  void transformProgram(Program program) {
+  void performModularTransformations(Program program) {
     new mix.MixinFullResolution().transform(program);
+  }
+
+  void performGlobalTransformations(Program program) {

[asgerf, 2017/02/02 11:46:00]

The transformations here are not global, I think.

[Kevin Millikin (Google), 2017/02/02 12:03:48]

They're just not rewritten in this change to skip external libraries.  Some of
them might work, but I didn't verify that.

setup_builtin_library is, unfortunately, global.  It violates the rule that the
dart: libraries cannot depend on the application.

     cont.transformProgram(program);
 
     // Repair `_getMainClosure()` function in dart:{_builtin,ui} libraries.